By almost every measure -- winning percentage, playoff appearances, championships -- the San Antonio Spurs are the most successful North American franchise of the past 15 years.

As with every dynasty, the Spurs owe their success to a combination of factors (scouting, coaching, luck, etc.). But in looking at this San Antonio squad -- you know, the one giving the Miami Heat a run for its money in the NBA Finals -- it's impossible not to notice one characteristic that separates the franchise from other teams. Namely, the Spurs have relied heavily on a plethora of foreign born players.

Two of the Spurs' "Big Three" -- Tony Parker and Manu Ginobili -- come from outside the United States. Tim Duncan, San Antonio's legendary big man, was born in the U.S. Virgin Islands but played collegiately in the United States and represented the United States in the Olympics.

This year the Spurs feature several key foreign role players in Tiago Splitter (Brazil) and Boris Diaw (France). Add in Patty Mills (Australia), Aron Baynes (Australia), Cory Joseph (Canada) and Nando De Colo (France), and more than half of the players on San Antonio's roster were not born in the continental United States. The eight foreigners on the Spurs constitute the most in the NBA in a season when there were a record number of foreigners.

As you might have suspected, this is not a coincidence. In a brilliant and revealing ESPN The Magazine story by Seth Wickersham, Spurs coach Gregg Popovich says foreign players are "fundamentally harder working than most American kids."

This work ethic is a result of many factors, perhaps none more important than the development systems in foreign countries:

"...when Pop looks at American talent he sees many players who "have been coddled since eighth, ninth, 10th grade by various factions or groups of people. But the foreign kids don't live with that. So they don't feel entitled," he says, noting how many clubs work on fundamentals in two-a-day practices, each lasting up to three hours. "Now, you can't paint it with too wide of a brush, but in general, that's a fact."

It definitely seems like Popovich has a point. Not only has he been scouting international players for decades, plus it's impossible to argue with the Spurs' remarkable and sustained success.